/*
 *    WriteStreamToARFFFile.java
 *    Copyright (C) 2007 University of Waikato, Hamilton, New Zealand
 *    @author Richard Kirkby (rkirkby@cs.waikato.ac.nz)
 *
 *    This program is free software; you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation; either version 2 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package moa.tasks;

import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.Writer;

import moa.core.ObjectRepository;
import moa.options.ClassOption;
import moa.options.FileOption;
import moa.options.FlagOption;
import moa.options.IntOption;
import moa.streams.InstanceStream;

public class WriteStreamToARFFFile extends MainTask {

	@Override
	public String getPurposeString() {
		return "Outputs a stream to an ARFF file.";
	}
	
	private static final long serialVersionUID = 1L;

	public ClassOption streamOption = new ClassOption("stream", 's',
			"Stream to write.", InstanceStream.class,
			"generators.RandomTreeGenerator");

	public FileOption arffFileOption = new FileOption("arffFile", 'f',
			"Destination ARFF file.", null, "arff", true);

	public IntOption maxInstancesOption = new IntOption("maxInstances", 'm',
			"Maximum number of instances to write to file.", 10000000, 0,
			Integer.MAX_VALUE);

	public FlagOption suppressHeaderOption = new FlagOption("suppressHeader",
			'h', "Suppress header from output.");

	@Override
	protected Object doMainTask(TaskMonitor monitor, ObjectRepository repository) {
		InstanceStream stream = (InstanceStream) getPreparedClassOption(this.streamOption);
		File destFile = this.arffFileOption.getFile();
		if (destFile != null) {
			try {
				Writer w = new BufferedWriter(new FileWriter(destFile));
				monitor.setCurrentActivityDescription("Writing stream to ARFF");
				if (!this.suppressHeaderOption.isSet()) {
					w.write(stream.getHeader().toString());
					w.write("\n");
				}
				int numWritten = 0;
				while ((numWritten < this.maxInstancesOption.getValue())
						&& stream.hasMoreInstances()) {
					w.write(stream.nextInstance().toString());
					w.write("\n");
					numWritten++;
				}
				w.close();
			} catch (Exception ex) {
				throw new RuntimeException(
						"Failed writing to file " + destFile, ex);
			}
			return new String("Stream written to ARFF file " + destFile);
		}
		throw new IllegalArgumentException("No destination file to write to.");
	}

	public Class<?> getTaskResultType() {
		return String.class;
	}

}
